Cast iron alloy



CAST IRON ALLOY Tage Debusmann Madsen, Goteborg, Sweden No Drawing. Application September 25, 1953, Serial No. 382,475

Claims. (Cl. 75-125) This invention relates to the manufacture of cast iron alloy for use in the production of cylinder liners of piston machines.

The wearing in the cylinders of piston machines originates from a friction effect which arises when the piston rings and also the piston under pressure glide against the cylinder wall. The wear can be further increased due to corrosion which arises by the attacking action of chemical compositions which are formed, e. g., by combustion gases in combustion engines or may be present in the scavenging air or in the lubricating oil and in compressors and pumps under normal working.

In almost every case, cast iron is used for the manufacture of cylinders, and one is especially pretentious concerning the structure of same in relation to the quality of hardness. It is already known to construct cylinders in cast iron alloy in order to increase the strength and to obtain a'great hardness in order, during manufacture, to control the forming of the structure in a better way and thus increase the resistance against wearing. For this purpose, alloys with chrome, with chrome and molybdenum, with chrome and nickel, also with chrome, nickel and molybdenum and furthermore with vanadium have previously been proposed; in all'these cases with or without an admixture of copper.

Experiments and practical experiences have proved that it is suitable to alloy cast iron cylinders, especially such cylinders having substantial dimensions, with vanadium, titanium and copper at which-in order to reduce wearing to a minimum as an influence summed up of resistance against friction as Well as against corrosionthe quantities of the different alloy elements should be as follows:

The upper limit for the content of vanadium can suitably be at about 0.5% and the lower limit at about 0.15%. The most convenient content will be at about 0.3%.

Corresponding to the dimensions of the cylinder liners and according to the wearing stresses in the particular cases and the temperature stresses and the conditions in question for the corroding attacks, the following alloy proportion: have proved to be especially suitable:

Ti=0.06% to 0.10% Cu=0.75% to 0.90% 2. v=0.2$%

Ti=0.10% to 0.14% Cu=1.00% to 1.25% 3. V=0.35%

Ti=0.l2% to 0.16% Cu=l.00% to 1.25%

United States Patent 0 p CC Ti=0.15% to 0.20% Cl1=1.00% to 1.25% Sb= 0.10% it) 0.12% 5. V=0.45%

Ti=0.15% O 0.20% Cu=l.50% to 1.75%

In all the five cases the remainder essentially consists of cast iron.

Small quantities of antimony (Sb) have proved to be further wearing reducing.

At moulding of different wall thicknesses the contents of carbon and silicon of the cylinder liners must be chosen so as to obtain the structure and the hardness aimed at.

It is advisable to harden the surface of the cylinder liner in any way know per se. Flame hardening and induction hardening can be used.

I claim:

1. Cast iron alloyed with vanadium, titanium and copper for cylinder liners of piston machines, especially of combustion engines wherein the proportions of the alloy elements are as follows:

the content vanadium ranging from 0.15% to 0.50%.

2. Cast iron alloyed with vanadium, titanium and copper for cylinder liners of piston machines, especially of combustion engines, wherein the proportions of the alloy elements are as follows:

the content of vanadium ranging from 0.15% to 0.50%. 4. A cylinder liner according to claim 3, which has been heat treated to attain greater hardness.

5. A method for the production of cylinder liners of I cast iron alloyed with vanadium, titanium and copper for cylinder liners of piston machines, especially of combustion engines wherein the proportions of the alloy elements are as follows:

Ti=%A% to %A% Cu=2A% to 6A% the content of vanadium ranging from 0.15 to 0.50%,

their cylindrical surface being given an external hardness by a surface hardening method known per se, e. g. flame hardening or induction hardening.

References Cited in the file of this patent Alloy Cast Iron: Handbook, 2nd edition, pages 14, 15 and 252. Published in 1944 by the American Foundrymen': Assm, Chicago, Illinois. 

1. CAST IRON ALLOYED WITH VANADIUM, TITANIUM AND COPPER FOR CYLINDER LINERS OF PISTON MACHINES, ESPECIALLY OF COMBUSTION ENGINES WHEREIN THE PROPORTIONS OF THE ALLOY ELEMENTS ARE AS FOLLOWS: 